Safety pilot burner



June 16, 1942. T. B. FOCKE ET AL SAFETY PILOT BURNER 7 Filed 001;; 20, 1939 3 Sheets-Shed l ATTORNEYS.

FIG. 2.

' INVENTORS. THEODORE B. FOCKE' ALLEN. K PHELPS June 16, 1942.

T. B. FOCKE ET AL SAFETY PILOT BURNER Filed Oct. 20, 1939 3 Sheeis-Shegt 2 FIG. 3.

INVENTORS. TH EODOBE- 5. FOCKE ALLEN I. PHELPS M,M m

ATTORNEYS.

June 16, 1942. T. B. FOCKE ET AL 2,286,610

SAFETY P ILOT BURNER Filed Oct. 20, 1959 3 h et s INVENTORS. THEODORE B FOCKE- BY ALLEN K. PHELPS ATTORNEYS.

Patented June 16, 1942 SAFETY PILOT BURNER Theodore B. Focke, Cleveland Heights, and Allen K. Phelps, East Cleveland, Ohio, assignors to Perfection Stove Company, Cleveland, Ohio, a

corporation of Ohio Application October 20, 1939, Serial No. 300,438

5 Claims.

This invention relates, generally, to fluid fuel combustion apparatus, and it has to do particularly with a novel form of pilot burner for use with such apparatus and a safety control system involving the same.

To the end of safety, our invention has, as its primary object, to provide, in combination with one or more main fluid fuel burners, a unique fluid fuel pilot burner and a control system involving the same by which a supply of fuel to the main burner or burners is permittedonly in case the pilot burner is functioning properly to light said main burner or burners.

Another object is to provide a convenient and reliable lighting means for the pilot burner; and, according to one form of the invention, to combine with such lighting means a control that acts to shut off the fuel supply to the pilot burner in case its flame accidentally becomes extinguish l, and which serves to re-establish the fuel supply to the pilot burner upon subsequent actuation of the lighting means.

Further and more limited objects are: to provide, in conjunctf on with one or more main burners, a plural jet pilot burner including means for effectively communicating combustion from one jet to another; to .combine therewith an igniter arranged in lighting relation to one of said jets, and a heat energized instrumentality that controls the supply of fuel to the main burner or I" burners and is arranged in heat receiving relation to another jet, and, still more limitedly, to provide, in association with a plurality of main burners, an elongated pilot burner possessing the foregoing features arranged with the igniter at one end, the heat energized instrumentality at the other, and the lighting jets for the main burners therebetween so as to insure against delivery of fuel to the main burners unless the pilot burner is properly functioning.

The foregoing objects and advantages, with others hereinafter appearing. including simplicity and economy of construction, facility of assembly and installation, reliability and durability are attained in the embodiments of the invention a diagrammatic representation of one form of the invention; and Fig. 7 is a similar view-showing.

- another form thereof.

' legs H from a base l2.

bly, designated generally by the numeral I5, is

While our invention is applicable to various kinds of combustion apparatus, we have selected as an illustration of a practical application its incorporation in the combustion apparatus of a gas fired furnace. Only such elements of the apparatus are included in the drawings as are essential to a proper disclosure of the invention, and in this connection it may be explained that the diagrams of Figs. 6 and '7 have been simplified by omitting therefrom all features ordinarily included in such control systems but which have no bearing on the instant invention.

The invention, in its broader'aspect, isappli cable to one or more main burners, or to, a multiple main burner of two or more independent sections or units. According to the illustrative embodiments herein disclosed, there are three such burners or units, designated l, 2 and 3. A mixture of primary air and gas is supplied to each burner or unit through an inducer 5 whose outer end incorporates the usual shutter-con trolled air mixer B into which fluid, fuel or gas is projected through a nipple 9 from a manifold 10. Asshown in Fig. 2, each inducer 5, with a burner mounted thereon, is supported through The pilot burner assemsupported from the base l2, in operative relation to the main burners, by standards iii to the upper ends of which are connected. by bolts i3, brackets body and cover with a part of the cover broken away; Fig. 5 is a section on the line 55 of Fig. 4 on a scale twice that of the latter view; Fig. 6

apertures are relatively small and comparatively.

closely spaced perforations 29 that provide the fuel to transmit combustion from one jet to an- 3 7 other, this end being further served by an over;- hanging cover 36 that is substantially L-sloaped;

in cross section and has the rear edge ,ofits,

wall welded or otherwise secured to thetop the burner body. The front wall of' the cover is cut away at its ends, as indicated atfll, and intermediate its ends is provided with a notch s2, soas not to interfere with the lighting jets projected from the apertures 26, 2'! and 28.

the attachment of conductors.

I joins the body 25 toward one end thereof, The

brackets 20 and 2| include laterally extending flanges or ledges 48 and ll, respectively, and supported by a mounting 48 from the ledge 48 is an electric igniter designated generally by the reference numeral 85.

The igniter consists of a body 88 of suitable insulating refractory material, and a resistor coil 81 disposed within a groove thereof. The ends of the coil are connected to screws 48 that extend through the body and have nuts applied to their ends, thereby to provide binding posts-for The parts are so arranged as to dispose the igniter in line with the aperture 34 so that a jet of fuel issuing therefrom will impinge against the resistance coil and be ignited thereby when said coil is energized. As will be readily understood, combustion from this igniting jet will be instantly transmitted through fuel escaping from the adjacent slot 38 to the jet of fuel projected from the aperture 26. The flame from the last mentioned jet is propagated along the line of perforations 28 beneath the cover 30 to the jets of fuel issuing from the apertures 21, and 28, from the latter of which combustion is transmitted by the fuel issuing from the slot 31 to that issuing from the aperture 35, the latter providing what may be termed the heating jet. Supported by the flange or ledge ll of the bracket 2| is a heat energized instrumentality or thermosensitive element 58, the one illustrated being a thermocouple which has the capacity to generate electric current when heated. This element is arranged for impingement against it of the aforesaid heating J'et.

Referring now to the diagram of Fig. 6, fluid fuel is supplied from a suitable source to the main burners I, 2 and 3 through a pipe 55 that is connected to the manifold l0. Included in the gas supply line or pipe 55 is an automatic valve 56 that is biased toward closed position, as by gravity, and is adapted to be opened by electrical means, such as a solenoid 51. A pipe 58 is shown as leading from the pipe 55, in advance of the valve 58, to the pilot burner, and the supply pipe may be equipped with a manual valve 58 in advance of its connection with the pipe 58.

60 designates a transformer, the primary winding 80 of which is in the house circuit that may be of the usual I I8 volts and is represented by the conductors GI and 82. The secondary winding 88 of the transformer is placed in circuit with the igniter 45 through conductors 83 and 64, the latter including a push button switch 85. Through conductors 81 and 88, the thermocouple 50 is placed in' circuit with the winding of a relay I0, whose armature H is normally held away from the core of the relay by a light spring 72. When energized, the relay moves the armature ll into engagement with a contact 13. represents a thermostatic switch or so-called room thermostat that is subjected to the heat output of the combustion apparatus or furnace.

According to the simplified control system herein disclosed for illustrative purposes, the room thermostat, under the influence of a temperature of given value for the maintenance of which it is set, and with the main burners out of operation and only the pilot burner functioning, is in condition to maintain the circuit in which it is included open. Assuming that the manual valve 58 is adjusted to supply fuel to the apparatus, gas will issue from the several :Iet apertures of the pilot burner, the igniting jet impinging against the resistance coil of the .igniter 45. To start the apparatus in operation, the push button switch-65 is closed thereby to establish a circuit through the secondary winding of the transformer, the conductor 63, igniter 45, and conductor 84. When the coil becomes sufliciently hot, it will ignite the gas issuing from the aperture 84, and combustion will be communicated therefrom across the slot 38 to the aperture 26 and along the row of perforations 28 to the apertures 21 and 28 and across the slot 81 to the aperture 35, the flame of the jet issuing from the latter aperture impinging against the thermocouple 50. When sufficiently heated, the thermocouple will generate current in the circuit represented by the conductors 81 and 68 and including the winding of the relay 10, thereby to energize the relay and attract the armature II so as to engage it with the contact 13. Assuming, now, that the temperature to which the room thermostat is subjected has fallen below the aforesaid given value, the movable contact member I6 of said thermostat will swing into engagement with the contact member 11, thereby to close the circuit including, besides the room thermostat, the secondary winding of the transformer, the solenoid 51, and the armature of the relay 10, said circuit being represented by the conductors I8, 18, and 8|.

It will be seen, therefore, that as long as the pilot burner is operating and heating the thermocouple 50, the relay III will function to maintain the circuit including the room thermostat and the solenoid 5! closed at the relay, thus placing the automatic valve 55 solely under the influence of the room thermostat to be opened when occasion requires.

The modification of the invention illustrated in Fig. 7 diflers from that shown in Fig. 6 only by the inclusion of an automatic valve for controlling the supply of fuel to the pilot burner, and a thermocouple, in association with the igniter 45, with its relay and necessary circuits. Therefore, in the diagram of Fig. 7, all parts corresponding to those of the diagram of Fig. 6 will be designated by the same reference numerals. In the form of the invention shown in Fig. '7, a pipe 58" that conducts gas from the supply pipe 55 to the pilot burner includes an automatic valve 85 that is biased toward closed position and is adapted to be opened by a solenoid 88. A thermocouple 88 is arranged in intimate heat exchanging relation to the igniter 45 and is desirably in the path of the Jet of gas issuing from the aperture 34. Through conductors 88 and 80, the thermocouple 88 is placed in circuit with the winding of a relay 8| whose armature 82 is held away from the core of the relay by a light spring 93. When the relay is energized, the armature 82 will be at-' tracted and swung into engagement with a contact member 84. The winding of the solenoid 86 and the armature of the relay 8| are placed in circuit with the secondary winding 60 of the transformer through conductors 86, 81 and88.

When the-parts are cold, the supply of gas to the pilot burner will be shut off by the automatic valve 85. When it is desired to set the apparatus in operation, the push button switch aaeaeio 65 is closed thereby to energize the igniter d5. When the temperature of the igniter becomes suficiently high to transmit enough heat to the thermocouple 88 to cause it to generate current, the relay 9! will be energized, thereby to swing the aperture 92 into engagement with the contact 94, establishing the circuit that includes the secondary winding of the transformer and the winding of the solenoid 86. Upon energization of the solenoid 88, the valve 85 will be opened to supply fuel to the pilot burner, and when the pilot burner is once in operation, the heat from the flame of the igniting jet will maintain the thermocouple 88 hot, thereby to supply current to the relay 9! and maintain closed the circuit including the solenoid 86 that acts, under such conditions, to hold the automatic valve 85 open. Should the flame of the pilot burner become accidentally extinguished, the thermocouple 88 will cool, thereby to deenergize the relay and open the circuit that includes the winding of the solenoid 88 and, as a consequence, allow the valve 85 to close.

Having thus described our invention, what we claim is:

1. A safety pilot burner comprising an elongated hollow bcdy having jet apertures spaced therealong and rows of perforations between apertures, a stationary cover extending along the body and permanently overhanging said perforations and cut away adjacent each aperture to prevent interference with the jet projected therefrom, and means for admitting fluid fuel to the body.

2. A safety pilot burner comprising a hollow elongated body having a plurality of jet apertures in its front wall spaced apart longitudinally thereof, one of said apertures being adjacent each end of the body, said front wall being provided also with perforations in series between said apertures, a stationary cover extending along the body and permanently overhanging said perforations and cut away adjacent each aperture to prevent interference with the jet issuing therefrom, the rear wall of the body being provided with apertures substantially diametrically opposite those apertures of the front wall that are adjacent the ends of the body, the bottom wall of the body having openings between the apertures of the rear wall and the corresponding apertures of the front wall, and means for admitting fluid fuel to the body.

3. A safety pilot burner comprising a hollow tures, a stationary cover fixed with respect to the body and permanently overhanging the front wall thereof and having a part extending downwardly in opposed relation to said wall, said part being cut away opposite each aperture, the rear wall of the body being provided with apertures substantially diametrically opposite those apertures of the front wall that are adjacent the ends of the body, the bottom wall of the body having openings between the apertures of the rear wall and the corresponding apertures of the front wall, and means for admitting fluid fuel to the body.

4. A safety pilot burner comprising a hollow elongated body having a plurality of jet aperelongated body having a plurality of jet apertures in its front wall spaced apart longitudinally tures in its front wall spaced apart longitudinally.

thereof, one of said apertures being adjacent each end of the body, said front wall having rows of perforations between said apertures, a stationary cover permanently overhanging the front portion of the body in opposed relation to the front wall thereof and cut away opposite each aperture, the rear wall of the body being provided with apertures substantially diametrically opposite those apertures of the front wall that are adjacent the ends of the body, the bottom wall of the body having openings between the corresponding apertures of the front and rear walls, supporting means secured to the body, one in the region of each of the apertures of the rear wall, and means for admitting fluid fuel to the body.

5. A safety pilot burner comprising a straight cylindricaltubular body closed at its ends, an inducer communicating with the body for admitting a fluid fuel mixture thereto, the front wall of the body being provided with jet apertures spaced apart longitudinally thereof, one of said apertures being located adjacent each end of the body, said front wall being provided also with perforations in series between said apertures, the rear wall of the body having jet apertures substantially diametrically opposite the apertures of the front wall that are adjacent the ends of the body while the bottom wall of the body has openings between the corresponding apertures of the front and rear walls, a cover fixedly attached to the top of the body and permanently overhanging the front side thereof and including a wall spaced from the front wall of the body in opposed relation thereto, said wall of the cover being cut away adjacent eachaperture of the front wall of the body to prevent interference with a jet issuing therefrom, and brackets secured to the body adjacentthe ends thereof, each bracket including a supporting part in the region of one of the apertures in the rear wall of the body.

' THEODORE B. FOCKE.

ALLEN K. PHELPS. 

